Circuitron Tortoise Switch Machines 5530 SD-3 SIGNAL DRIVER Bi-Color LED

Description

The CIRCUITRON SD-3 is capable of driving any single searchlight style, 2
lead or 3 lead, Bi-Color or Tri-Color, LEDtype signal to red, green and amber
aspects. Compatible signals are manufactured by Oregon Rail Supply, Tomar,
Sunrise Enterprises, ISS and others. Two SD-3s are required for double-head
signals. NOTE: The SD-3 will not drive 3 lamp signals (see SD-1 above). Bi-color
LEDs contain both a RED and a GREEN chip mounted side by side. Amber is achieved
by alternately lighting the red and green LED chips at a high frequency. The eye
perceives this mix of red and green as yellow (amber). A hue adjustment is
provided on the SD-3 to allow adjusting the amber color. The SD-3 may be
controlled by a single-pole, 3 position switch or automatically by detection
circuits such as the CIRCUITRON BD-1, BD-2 or BD-3 (minimum of 2 blocks
required). Other detection circuits that provide a logic low (ground or -)
output may also be used. The SD-3 is constructed on a 2 x 3 printed circuit
board and requires a 10 – 18 volts AC or DC input (a DC power source is required
when the SD-3 is used with detection circuits).